A New York prison seamstress helped two inmates escape by smuggling tools into prison inside of ground beef, a local prosecutor told NBC News Tuesday.

Clinton County District Attorney Andrew Wylie, whose office is prosecuting the escape plot of Richard Matt and David Sweat, said the prison tailor shop instructor embedded hack saw blades, drill bits and a hole punch in the meat before bringing it into Clinton Correctional Facility.

The convicted killers burrowed out of the maximum security prison in Dannemora, New York, on June 6.

Joyce Mitchell, who has been charged with providing escape tools to the fugitives, outlined the scheme in interviews with investigators, Wylie said…